Global RallyCross driver Marcus Grönholm will miss the Round 5 stop Sept. 29 at Las Vegas Motor Speedway while he recovers further from head injuries he suffered at X Games Los Angeles 2012.

The Finnish driver, who won the first two rounds of the season at Charlotte Motor Speedway and Texas Motor Speedway, will be replaced by international rallycross veteran Andreas Eriksson in the Best Buy Mobile Ford Fiesta, according to a news release by Marcus Grönholm Racing.

"I have worked hard on my rehabilitation since the accident at the X Games at the beginning of July. I feel fine, however doctors set a date in October in order to ensure I am 100 percent fit, so I cannot compete in Vegas and I will wait until the assessment before thinking about my next step," Grönholm said in the news release.

After Grönholm undergoes a full medical review in October, he will then decide whether he will race in the season finale Oct. 30 at the SEMA trade show at the Las Vegas Convention Center.

"I will however be in Las Vegas, and I can think of no-one better to fill in for me and keep the Best Buy Mobile challenge alive than Andreas. He is fast, but I can still give him some tips!" Grönholm said in the release.

Eriksson is CEO of OMSE, the team that prepares and manages the Ford Fiesta GRC, and substituted for Grönholm in a 2011 race at Snoqualmie, Wash., where he had first- and third-place finishes.

"Naturally Marcus is a very tough act to follow, but as a team, we want to maintain the positive momentum that Best Buy Mobile has in the series. So I will be trying my very best to emulate the success that Marcus has had this season and we will see how we get on in Las Vegas," Eriksson said in a release from Best Buy Racing.

Grönholm was discharged from the California Hospital Medical Center in Los Angeles on July 7 before returning home to Finland, where he has been resting and recovering. The 44-year-old Finn was knocked unconscious when his car hit an exposed light post base after clearing the jump during RallyCross practice on June 30.

No matter what results from his medical tests and consultations with doctors, the two-time World Rally champion still plans to be involved in racing 2013.

"Of course competing in a car in some shape or form is my preferred option, but I have been busy developing lots of ideas for next season, some involving active competition, some involving different roles outside of the car, which will be quite different for me, but still will be exciting and challenging in equal measure. This way I can move forward with a clear plan regardless of the doctors' verdict next month," Grönholm said in the release.